IN RECENT YEARS, TYPE-II SUPERLATTICES HAVE EXPERIENCED SIGNIFICANT DEVELOPMENT. HOWEVER, THE FULL POTENTIA…

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IN RECENT YEARS, TYPE-II SUPERLATTICES HAVE EXPERIENCED SIGNIFICANT DEVELOPMENT. HOWEVER, THE FULL POTENTIAL OF TYPE-II SUPERLATTICE HAS NOT BEEN FULLY EXPLORED AND ALTERNATE SUPERLATTICE ARCHITECTURES HOLD GREAT PROMISE. DESPITE DEMONSTRATION OF SWIR PHOTODETECTORS BASED ON THIS MATERIAL SYSTEM, THERE HAS BEEN NO REPORT ABOUT TYPE-II SUPERLATTICE-BASED PHOTODETECTORS THAT HAVE BEEN SENSITIVE TO VISIBLE LIGHT. WE PROPOSE TO DEVELOP TYPE-II SUPERLATTICE-BASED PHOTODETECTORS AND FOCAL PLANE ARRAYS FOR NASA'S IMAGING AND SPECTROSCOPY APPLICATIONS IN THE SPECTRAL BAND FROM VISIBLE TO EXTENDED SHORT-WAVELENGTH INFRARED (0.4 2.5 UM) WITH A VERY LOW DARK CURRENT DENSITY. IN MID- AND LONG-WAVELENGTH INFRARED SPECTRAL BANDS, TYPE-II SUPERLATTICE-BASED PHOTODETECTORS ALREADY OFFERS PERFORMANCE COMPARABLE TO THE STATE-OF-THE-ART MERCURY CADMIUM TELLURIDE BUT AT A FRACTION OF THE COST DUE TO THE LEVERAGING OF COMMERCIAL GROWTH AND PROCESS EQUIPMENT. OUR GOAL IS TO EXTEND THAT BENEFIT INTO THE SHORT-WAVELENGTH INFRARED. USING THE BEST MATERIAL CURRENTLY AVAILABLE AND A NOVEL BANDGAPENGINEERING DESIGN AND PROCESS, WE WILL FABRICATE PHOTODETECTORS AND, ULTIMATELY, FOCAL PLANE ARRAYS. IN PHASE I, WE ARE GOING TO DEMONSTRATE PHOTODETECTOR DESIGNS BASED ON TYPE-II SUPERLATTICES, WHICH CAN COVER SPECTRAL RANGE BETWEEN 0.4 TO 2.5 UM WITH A VERY LOW DARK CURRENT DENSITY (<10^(-11) A/CM2) AT TEMPERATURES BELOW 100 K.. IN PHASE II, WE ARE GOING TO CONTINUE REDUCTION OF THE DARK CURRENT DENSITY TO<10^(-13) A/CM2-LEVEL AT TEMPERATURES BELOW 100K. THEN, WE WILL USE THE OPTIMIZED DEVICE DESIGN TO DEVELOP AND DELIVER 1K 1K IMAGERS TO NASA FOR PLANETARY SCIENCES.